The regulation of breathing gas by high pressure regulators is common to that required to regulate the flow of gas from a high pressure to an intermediate source. Such regulators are known in self-contained breathing apparatus such as for use by divers. Generally, the first stage or high pressure regulator regulates upwards of 3,500 psi gas to an intermediate or lower pressure. The regulation can be from the high pressure source of 3,500 psi down to approximately 120 to 140 psi.
After the first stage regulation of the high pressure gas, a demand or second stage regulator can be utilized for a diver using self-contained breathing apparatus. The demand regulator generally functions by inhalation creating movement of a diaphragm which in turn operates a valve that is linked to it. Upon the demand regulator valve opening, the first stage or high pressure regulator then regulates flow from the source, such as a high pressure tank.
This invention is concerned with regulation of the high pressure source to a second stage or demand regulator. Such regulators are known to have a diaphragm that is exposed to ambient pressure. The regulators are utilized with self-contained breathing apparatus used for industrial or firemen's safety equipment, as well as self-contained underwater breathing apparatus. Oftentimes, the high pressure regulator is attached to a valve of a tank by means of a yoke and a threaded securement. The high pressure source is allowed to flow into the regulator and after regulation, to the intermediate or demand regulator.
Such high pressure or first stage regulators generally have an operating diaphragm. The operating diaphragm is provided with a main spring for balancing against a spring pad and a spring support and spring adjustment screw. In effect, the diaphragm is maintained by the spring in a position to provide for opening and closing of the valve seat over a crown.
The area within the space occupied by the main spring, namely that between the spring support and adjustment screw and the spring pad is filled with a pressure coupling fluid such as a silicone oil. In some regulators in the past the diaphragm was directly exposed to ambient conditions. However, it has been found preferable to fill the space with silicone oil especially when the regulator is exposed to freezing conditions.
The spring support and adjustment screw is usually threaded into the side walls of the regulator and provided with a slot or keyway in order to threadably adjust it within the sidewalls to increase or decrease the compression on the spring.
Overlying the silicone oil and the spring support and adjustment as well as the spring is a covering or ambient sensing diaphragm. The diaphragm is maintained within the regulator body by means of a diaphragm retainer. The diaphragm overlays the adjustable spring support in the prior art. It had to be removed in order to adjust the spring support to vary the compression on the main spring.
When the diaphragm was removed by unthreading the diaphragm retainer, it became a complex operation due to the fact that silicone oil was utilized in the regulator. This caused innumerable problems in being able to adjust and maintain the compression of the main spring.
In order to overcome these adjustment problems, regulators were often times taken to a workshop or laboratory environment rather than adjusting them in the field. This being the case, a diver in the field could not easily adjust the regulators and found himself subject to adverse conditions.
This invention provides for adjustment of the regulator main spring without removal of the diaphragm. This avoids exposure of the liquid silicone to prevent spilling or for that matter contamination of the interior parts of the regulator.
In order to effectuate this, an adjustable spring support is provided with a stem and screw means extending through the covering diaphragm. The diaphragm is specifically oriented so as to allow for the stem of the adjustment screw for the regulator to pass therethrough and yet still seal the silicone oil behind the diaphragm.
The covering diaphragm is effectively seated into the regulator side walls and held therein by means of a diaphragm retainer. A screw means with a stem extends through the diaphragm and serves to provide the adjustment screw with proportional movement to allow it to move within the walls of the regulator. This attendantly avoids a disassembly of the regulator as is known in the prior art with the removal of the diaphragm and exposure of the interior of the regulator including the liquid silicone. Consequently, this invention is a substantial step over the prior art by allowing for improved regulator adjustment of a regulator having a diaphragm and fluid coupling oil.